He said "lives would be lost" if politicians and the authorities on both sides of the border did not properly prioritise and resource the issue.

"More than 830 staff and their families and the wider community are impacted by this violence and intimidation and they are in urgent need of reassurance that this issue is being taken seriously," he added.

Gardaí said they had attended an incident of criminal damage, but that no injuries were reported and investigations are ongoing.

Sean Quinn was once the richest person in Ireland, a self-made man who started a multi-billion pound business empire by selling gravel quarried from his family's farm in Derrylin, County Fermanagh.

The Quinn Group gradually expanded, manufacturing and supplying other building products, glass and plastics, and eventually moved into insurance, hotels and property development.

His business empire collapsed after Mr Quinn made a disastrous investment in Anglo Irish Bank.

He lost control of his business empire and was declared bankrupt in 2012.

A previous campaign of attacks in 2013 and 2014 included an oil tanker being driven into the company headquarters in Derrylin and set on fire.

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A few years ago there were frequent attacks on businesses linked to former Quinn companies

A group of businessmen backed by three investment funds bought the manufacturing businesses in December 2014.

They are run by former close associates of Mr Quinn.

After he was discharged from bankruptcy, Mr Quinn was employed as a consultant at his former company.

He left the role in May 2016 as tension grew between him and the management team.